Sound-deadening plate and method of making same



W. GENEST March 18, 1930.

SOUND DEADENING PLATE AND METHOD OF MAKING SAME Filed March 6, 1926nwsuron 4 Patented Mar. 18, 1930 UNITED Z1;

Pr r oF ICE Y WERNER GENEST, OF IBER LIN-LICHTERFE -LDE, GERMANY, ASSIGNOR TO THE KOBIlI'l'ND COMPANY, INC., OFNEW YORK, N. Y., A CORPORATIONOF NEW YORK sounn-nnannmne PLATE AND Mnrnon or MAKING SAME Applicationfiled March 6, 1926, Serial No.

The subject of the invention is a process employed to regulate theelasticity of plates used under the foundation of machinery of all typesfor the purpose of preventing or 6 dampening the transmission of noiseand vibration. Plates of this kind are made of strips of cork preferablynaturally grown cork. This material has a certain elasticity and naturalfrequency depending upon the 10 grade of the cork. As the ability of thecork plates to isolate against the transmission of noise and vibrationdepends on the elasticity of the cork in as far as an increase in theelasticity also increases the ability of the cork to isolate, theelasticity of the cork may longitudinally with respect to the directionof the grain of the cork, and laterally with respectto the direction ofthe grain of the cork preferably before the cork strips have been placedinto the cork plates. The rollers can be mounted in such a manner thatthe axes of the set or sets of rollers which exert pressurelongitudinally with respect tothe grain of the cork, are at right anglesto the axes of the other set or sets of rollers which exert pressurelaterally with respect to the direction of the grain of the cork, aswill be more fully explained hereinafter. If necessary several sets ofrollers in this position can be arranged one behind the other. Therollers of the second and following sets can be placed somewhat closertogether than of the first set. It is important that the naturalfrequency of theisolating material be difierent from the frequency ofthe vibration of the machine to be isolated, to avoid harmonicvibrations. If the frequency of the machines vibrations is the same asthe natural frequency of the isolating members which support themachine, then the vibrations of the two will tend to harmonize and thoseof the isolating member and of the machine will become excessive. I

Reference being made to the accompanying diagrammatic drawings, j

Figure 1 is a horizontal cross section of a 92,984,'anr1 in GermanyMarch 13, 192 5.,

cork tree and Figure 2 is a vertical cross section of a cork treeillustrating the direction of the grain of the cork in the bark of thecork tree. I

Figure 3 1s a side elevation illustrating a strip of cork passingbetween sets of rollers.

used in subjecting the cork to pressure in cordancewith the presentinvention.

Figure 4 is a top plan View of the cork strip and rollers shown inFigure 3.

In Figures 1 and 2,1 indicates thetrunk of the cork tree, 2, the corkbark, and 3, the direction of the grain of the corkwhich runs at rightangles to the trunk of the tree.

In carrying out the present invention, a strip of cork 4 is passedbetween one or more pairs of opposed ollers 5, 67, 8 9, 10'11,

12. The rollers 5, 6 and 7, 8'eXert temporary pressure on thecor'klongitudinally with respect to the direction of the grain of thecork while the rollers 9, 1011, 12 exert temporary pressure on the corklaterally with re spect to the direction of the grain. I

The cork strip is first passed between the rollers 5, 6-7, 8, the latterset of rollers be ing spaced closer'than the rollers 5, 6 wherebygreater pressure is exerted on the cork strip by the more closely spacedrollers. The cork strip then passes between the rollers 9, 10 and 11,12, the latter rollers of 11, 12 being likewise spaced closer than therollers 9, 10,

whereby greater lateral pressure is exerted on the cork strip than isexerted by therollers j l/Vhile I have shown two sets of rollersexerting pressure longitudinally and laterally on the cork strip withrespect to the direction i of the grain, it is to be understood that theroller 7, 8 and 11, 12 could' be dispensedwith or additional sets ofrollers could be added without departing from the spirit of myinvention.

'The rollers 5, 6-7, 8,9, 10-11, 12 may be mounted in adjustablebrackets or bearings upon a suitable frame and may be rotated by anywell-known form of drive mechanism.

Through the regulation of the pressure of i the rollers or the speedwith which the cork, 1

strips pass through the rollers and of the number of sets of rollersarranged one behind V 2 a V 1,751,320

the other, it is possible to regulate the elasticity of the corkmaterial within wide limits.

Through the increased elasticity of the cork 7 strips the ability of thecork plates-composed sf cork strips to isolate against noise andvibrationis greatly increased.

Having thus described the nature of my invention I claim:

:1. A sound deadening plate consisting of anunib'erofcork.strips each ofwhichis compressed laterallyand longitudinally With1respect to thedirection of the grain of the cork. 2. The method of regulating theelasticity of sound deadening plates which consists in subjecting therespective cork strips thereof to varying lateral and longitudinalpressures with respect tothegrain otthe cork.

3. The method of manufacturing sound deadening plates wherein aplurality .ofcork strips are employedto .form the plate, which'cons'istsin passing each cork strip of the plate between pairsof'opposed rolls, the axes of certain of whichare disposed at rightangles to the others.

L The method of manufacturing sound deadening plates wherein apluralityof cork strips'are employed to formthe plate, which i consists inapplyingpressure to each strip both longitudinallyand laterally relativeto grain of the cork when said strip is :passingbetween a series ofopposed rolls.

Intestnn0ny,that-I claim the foregolng as my invent on I have signed myname.

WERNER GENEST,

